Planetfall is many people's favorite IF of all time, so I knew it would be hard for it to live up to the hype. However, I think I just don't like Meretzky's style (e.g. Sorceror, the puzzles in Hitchhiker's Guide, etc.). He tends to favor big, mostly-empty complexes with many useless items thrown in to make it hard to find the real puzzles.
This worked for me in A Mind Forever Voyaging, but in Planetfall, I felt like I was just walking through an abandoned warehouse. I much prefer Moriarity's tightly-interlocking puzzle style, or Lebling and Blank's rich puzzle variety.
In planetfall, you play a lowly ensign in space who crash lands on a deserted planet, meeting a friendly robot named Floyd and trying to discover what happened. The resolution of the puzzles and storyline is satisfying, and the writing has several high points.
I recommend this game, but not as high as the Enchanter trilogy, Moriarity's games, or even Ballyhoo, which I loved.